Finding the Fourth Proportional to 99.89, 137.82 and 58.42

Step by Step Solution

1. Step 1: Write the proportion equation
   99.89 : 137.82 = 58.42 : x
2. Step 2: Convert to fraction form
   99.89/137.82 = 58.42/x
3. Step 3: Cross multiply
   99.89x = 137.82 × 58.42
4. Step 4: Simplify right side
   99.89x = 8,051.10
5. Step 5: Solve for x
   x = 8,051.10/99.89
6. Step 6: Final answer
   x = 80.60